Untreated depression in late-life can lead to negative individual, family, and societal consequences such as poor overall health, increased disability, medical morbidity, mortality, suicide risk, and higher health care utilization and costs. Quality improvement interventions to facilitate antidepressant therapies from the primary care physician have been found to be effective, yet a potential barrier to depression management is the integration of mental health practitioners within primary care practices. In this pilot study, we will explore the feasibility, acceptability, and effectiveness of adding individually administered Problem Solving Therapy (PST) to enhanced usual care as an approach for treating depression in adult day health care (ADHC) for predominantly low-income Latinos with depression and significant comorbid medical illnesses. All study patients will receive usual ADHC care modestly enhanced with Patient Navigation (PN). In PN, the ADHC's usual care BSW will routinely screen patients using the PHQ-9, provide "bridging communication" with the patient's primary care physician (PCP) to facilitate guideline-consistent antidepressant treatment, monitor patient's symptoms on a bi-monthly basis and report results to the PCP. In addition, half of the subjects in the study will be randomly assigned to receive PST from a bachelor's-degreed licensed clinical social worker (LCSW). Intended for persons in need of treatment for multiple, chronic health conditions, ADHC delays or prevents higher cost skilled nursing care through an array of medical, rehabilitative and social services provided in a licensed day center. ADHC also has organizational design characteristics that are likely to facilitate access and receipt of evidence-based depression care. Applying their skills within a biopsychosocial approach to assessment, planning and coordination, and in multi-system interventions, social workers are an integral part of the ADHC multidisciplinary team. Based on our previous work and that of others, PST has been found to be acceptable to middle-age and older English- and Spanish speaking Latinos. We will draw from existing manualized PST protocols and sociocultural enhancements for medically-ill adults and low-income Latinos to increase the acceptability of PST. The long-term goal is to develop pilot implementation data as a basis for a larger scale randomized trial in diverse ADHC programs. Untreated depression in late-life can lead to negative consequences such as poor overall health, increased disability, medical morbidity, mortality, suicide risk, and higher health care utilization and costs. The randomized pilot study of 90 Medicaid-eligible geriatric patients with major depression will test the feasibility, acceptability, and effectiveness of providing evidence-based, socioculturally-acceptable psychotherapy to decrease the burden of mental illness and disparities in geriatric mental health.